在eacheach绑定中的knockoutjs单击绑定 [英] knockoutjs click binding within foreach binding

问题描述

问题与绑定无关，而与简单的JavaScript错误有关.

我有一个关于foreach绑定内的单击绑定的问题. 我有一个列表，其中包含显示下拉框的项目，以便从主数据中选择一个值.可以在该列表中添加和删除项目. 删除项目的按钮嵌套在foreach绑定中.因此，我希望我应该将其与$ parent>

I have a question concerning a click binding within a foreach binding. I have a list with items showing a drop down box to select a value from the master data. Items can be added and removed from that list. The button to remove items is nested in the foreach binding. Therefore I expected that I should bind it with $parent>

<button data-bind="click: $parent.removeNumber">-</button>

那是行不通的.但是以下版本适用:

That does not work. But the following version works:

<button data-bind="click: removeNumber">-</button>

我不明白为什么.

代码:

<h2>numbers:</h2>
 <ul data-bind="foreach: numbers">
     <li>
       <select data-bind="value: id, 
                          options: masterData, 
                          optionsText: 'caption', 
                          optionsValue: 'id'"></select>
        <br />
        value: <span data-bind="text: id"></span>
        <br />
        <button data-bind="click: $parent.removeNumber">-</button>      
    </li>
</ul>
<button data-bind="click: addNumber">+</button>

function ViewModel() {
    self.masterData = [{ id: 1, caption: "One"},
                       { id: 2, caption: "Two"}];

   self.numbers = ko.observableArray([{
        id: ko.observable(2)}]);

    self.addNumber = function() {
        self.numbers.push({
            id: ko.observable(2)
        });
    };


    self.removeNumber = function(item) {
        self.numbers.destroy(item);
        console.log("removed" + item);
    };
}

var viewModel = new ViewModel();
ko.applyBindings(viewModel);​

我创建了一个小提琴(使用不起作用的版本): http://jsfiddle.net/delixfe/NWWH8/

I have created a fiddle (with the not working version): http://jsfiddle.net/delixfe/NWWH8/

感谢您的帮助.

推荐答案

您让我有一秒钟！

您是正确的，应该输入$parent.您的错误是没有在视图模型中定义self.之后，removeButton和masterData绑定都需要$parent.

You are correct, $parent should be required. Your mistake was not defining self in your viewmodel. After doing that, $parent was required on the removeButton, as well as the masterData binding.

这是一个有效的小提琴: http://jsfiddle.net/FpSWb/

Here is a working fiddle: http://jsfiddle.net/FpSWb/

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